The evolution of the NFL:
Take a look at how the NFL has evolved from its humble roots, and the efforts being made to ensure it continues to grow.

"Yesterday I made the difficult decision to retire from the game of football," Ballard said in a statement, via ProFootballTalk. "I love this game and have put my heart and soul into it for as long as I can remember. After sustaining a serious knee injury while playing for the New York Giants in the Super Bowl, my body never felt the same.

"Having a quality of life after football is very important to me and I have witnessed it taken away from others. I will miss the game tremendously, but I am ready for this next chapter in my life."

Ballard memorably collapsed to the turf at Lucas Oil Stadium while trying to test out his knee in the fourth quarter of the Giants' Super Bowl XLVI win. Tests revealed that he'd suffered a torn ACL and cartilage damage that eventually required microfracture surgery.

Ballard was the subject of more Patriots-related intrigue when New England claimed him off waivers in 2012. The Giants had been attempting to pass the tight end through waivers before moving him to injured reserve. Widely hailed as a coup by Bill Belichick, the move turned out to be much ado about nothing.

Ballard was no longer the same player, a fact he now freely acknowledges.